Porous thin layered nanosheets assembled ZnCo2O4 grown on Ni-foam as an efficient electrode material for hybrid supercapacitor applications

Thin layered nanosheets of ZnCo2O4 with desirable porous nanoarchitecture grown on Nifoam were prepared using a simple surfactant free hydrothermal method. The Ni-foam supported ZnCo2O4 nanostructure was characterized using X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). FESEM clearly revealed thin nanosheets which were randomly connected together to form a porous structure. The binder-free Ni-foam supported ZnCo2O4 electrode was applied directly to hybrid supercapacitor analysis. In three electrode measurement, thin layered nanosheets of ZnCo2O4 exhibited a maximum specific capacity of 886 C g(-1) at a current density of 2 mA cm(-2). When the current density was increased from 2 to 50 mA cm(-2), the specific capacity value was 362.5 C g(-1). After 2000 continuous charge discharge cycles, about 94% of the maximum specific capacity was retained. This high specific capacity, better rate capacity, and excellent cyclic stability of thin layered nano sheets of ZnCo2O4 suggest that the prepared electrode is a promising candidate for hybrid supercapacitor applications. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.